


Inevitable

by thingsiwontadmittohavewritten



Category: Teen Wolf (TV)
Genre: Derek and Laura are mates, F/M, Implied vaginal sex, Knotting, Pre-Canon, Sibling Incest, The Hale Fire, implied sex
Language: English
Status: Completed
Published: 2016-12-08
Updated: 2016-12-08
Packaged: 2018-09-07 07:51:39
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, Underage
Chapters: 1
Words: 917
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8789674
Author URL: https://archiveofourown.org/users/thingsiwontadmittohavewritten/pseuds/thingsiwontadmittohavewritten
Summary: Derek had always known who his mate was





	

Derek had always known who his mate was; would’ve been difficult not to as they’d been sharing the same accommodations since their conception, and if he hadn’t gotten the message before it was rammed home by the time he was twelve and couldn’t get his eyes off of the first hesitant beginnings of breasts forming on Laura’s chest.  
But where Derek knew Laura seemed to be ignorant, always mercilessly teasing him with non-existing crushes, pranking him everywhere he turned and embarrassing him in school; and the worst part was how he let her, desperate for even a tiniest amount of attention from her – and when Laura pranked she gave it her all – but unable to retain it for long before Laura would turn it towards someone or something else.  
-  
And then it didn’t matter as his entire life went up in flames, the smell of charred wood and burnt flesh clogging up his nose making it impossible to breathe; rest; even eat, and when Laura flashed red eyes at him and dragged him to New York he was as much a burnt out shell as their uncle Peter in the nursing home.  
He hears her sometimes, crying as silently as she can not to disturb him but what shallow rest he finds in the darkness is not enough to block out the sting of salt in the air and the knowledge that he’s the reason they’re lying here; alone even in the midst of millions of people, even as close to each other as you can get in a two bedroom apartment in Manhattan.  
Other nights she crawls into his bed, arms winding around his waist holding him tight with crushing strength while sobbing into his shirt collar, him as stiff as a board awkwardly petting her hair; and then one night it spills out, every sin he’s ever committed every guilt placed upon his shoulders and all Laura does is drawing him closer, letting him crawl onto her lap and hide his face in her neck, her hair shielding him from view and at long last he lets go, tears and snot floating from him freely as he clings to his sister; alpha; mate.  
-  
It gets better then; glacially slowly perhaps but they’re together and one day Laura smiles at him and for the first time since he was met by a wall of fire is Derek capable of eating cooked meat without throwing everything right back up. Laura takes her GED wanting to study further but the thought of being confined indoors is too much for him and instead he goes in search of work – he end up in construction, takes to it like a fish to water and the best part is that he gets to sleep without nightmares for a few days a week. They establish a new kind of normal where they go out with friends, watch silly sitcoms and sleep in each other’s beds and slowly the feeling of being alone dissipates and even their loss takes a back seat as their lives go on.  
-  
But of course a string can only be stretched so far and the straw that breaks the camel’s back is when Laura’s getting ready to go out on Halloween. She’s wearing a white tie top and a pair of red checkered high-waist shorts, suspenders keeping them up and only revealing a small strip of skin between top and shorts. On her feet is a pair of white stockings ending just below her knees complete with a pair of seven inch stiletto heels matching the shorts. If the backside isn’t enough to make him want to tell her to change the front is. The first he notices is the little bows on the stockings, same pattern as the shorts and high enough tease at the skin of Laura’s knees; the second how the shorts extends upwards at the sides where the suspenders are fastened, framing her naked stomach all the way up to the knot of the top where the curve of her breasts are barely visible, fabric pulled tight across her breasts to squeeze them closer; and Derek had known that Laura’s not a scrawny twelve year old any more, but to be so blatantly presented with the evidence is more than he can be expected to handle, especially when it looks as if the white top is nothing more than a deep breath away from ripping at the seams, exposing his sister to who knows what and that’s not something Derek’s willing to risk, so in stead of backing up and letting Laura leave the room he takes a step forward, growl rumbling from his throat and he’s on her; pushing her down on the bed, straddling her hips and then _tearing_ the top apart, Laura’s breasts bouncing happily out of the restricting material, nipples hardening as they come into contact with the colder air and Derek is lost.  
It’s a frenzy of claws and fangs, growls and whines, clothes shredded to pieces and eyes flashing as they both try to gain the upper hand. Once he sinks inside her, her legs locked painfully tight around him, he sets a punishing speed not caring one bit that the wildness of his movements is making the bed knock against the wall. He comes with a howl muffled by his fangs extending into the tender flesh where shoulder meets neck, his knot locking him inside his sister and her voice filling his ear with one word:  
“Finally”

**Author's Note:**

> [Laura's costume front & back](https://www.amiclubwear.com/costume-schoolgirl-jj1-4755whitered.html)


End file.
